Acheron
by JAK Kinase
Summary: In the realm of Hades a doctor and an archaeologist wake. In-Progress. Chapter Three: Falling. Like usual.
1. Chapter 1

Disclaimer: Oda is genius. I'm not him. And I don't own.

* * *

"So this is Styx."

Mist rose off water in gentle, maddening rivulets – like small, ethereal waterfalls running in reverse. It was beautiful in an oddly endearing, mind-wrenching way. But then again, she was the one who had wanted to name the Sunny, 'Darkness Pill' so maybe her opinion wasn't particularly valid from the aesthetics standpoint.

Not that she cared what anyone else thought and still privately referred to it as Darkness Pill when the moon was queen and the sun just another of the hundreds of billions of distant suitors. Besides, she had things to take care of even if by all accounts she was waiting for Charon on the banks of some lonely island accompanied by an unconscious reindeer.

"R…R- Robin?"

Scratch the unconscious part.

"Doctor-san?" Once upon a time that smile in her voice, on her face, had been feigned.

"I… I failed us, didn't I?" Miserable. He was in his adorably cute human-reindeer hybrid form that for reasons that surpassed imagination and her considerable intellect, meant that he was about three feet tall. But because he was adorably, ridiculously cute she forgave him for being an open riddle with no answers and instead tilted the hat up he had pulled over his face to look straight into little, tearful reindeer eyes.

"You did your best. And none of the others are here."

It was true. She had checked.

"So your antidote got to them in time. You saved the crew, doctor-san. You found your panacea."

His eyes brightened. But then fell again.

"I couldn't save you."

* * *

"_You already did."_

* * *

It was a little while later, but finally Chopper asked: "Are we dead?"

"Probably."

Normally he'd be scared (funny how she could use the word 'normally' while dead), but right now all she could detect was resignation. She grabbed him close and seated him on her lap and together they watched the river of death for a while until she realized he was blubbering.

"It's okay, Doctor-san."

Sweet nothings. She hadn't quite grasped the concept the first time she had heard the expression. But maybe… maybe now she understood it a bit better. She wished there could be a sun, maybe a soft, perfect beach and pink cotton candy. Not a dark, grey ocean and stony, granite cliffs upon which to perch. While she might, he didn't belong here.

"There were… there were things I wanted to do and now…"

"Shhhh, it's okay, Doctor-san."

And then, many hours later, she discovered that even in the land of the dead one could fall asleep.

She smiled and hoped it was a good dream he was having.

And then she performed a minor experiment.

* * *

"Robin? Robin, what happened?"

Her clothes were wet. She was wet. He was hiding behind a rocky outcropping and for some reason, only hiding half his face instead of revealing only half, as might be expected from just about anyone else. Navigator-san had called it a reverse cartoon peek. Robin, despite all her learning, had never gotten the reference and Nami had laughed, a little like glass bells, and said it'd be too difficult to explain.

(Usopp and Luffy had appeared _devastated_ at this news and moped around muttering 'deprived… poor thing… never even see a real cartoon her-' until Sanji had announced lunch about two minutes later.)

"I'm not sure," she mumbled truthfully. Apparently one didn't drown during death. But still, she was _cold_.

"Robin – Robin, did you go _swimming?_"

And suddenly he was about two feet away, searching for the medical backpack that had clearly been left in the land of the living. At least he wasn't yelling for a doctor. Robin firmly guided him back to the rocky outcropping.

"I'm fine. See?"

After some poking and prodding Chopper determined that she was indeed fine and managed to stop hyperventilating.

Then he hit her. It was a reindeer punch in his cute-adorable form which felt whisper light for someone who had once traded blows with an admiral that could kick things at the speed of light but still.

"You can't do that!" Chopper said, crying and Robin realized he'd been scared. More scared than he had ever been, possibly. "You can't just leave like that. We promised, remember? After we got you back from Enies Lobby, I would make sure-"

"I remember," she told him, finger on his lips. "Next time I go swimming, I promise I'll tell you."

He frowned at her.

It was adorable. Really.

* * *

"Robin! Robin! I see someone! Riding a…"

He was at a loss for words and having witnessed him grind together plants with labels so esoteric she's the only one he's ever trusted to not have to spell the words out so they weren't mixed up with some other – possibly lethal – ingredient she was fairly certain it's not a vocabulary issue.

She sneaked open an eye.

There was a boy. Riding a… suit of armor. (Or the open chestpiece of one. Connected to legs, arms and helmet.) On a river. A supposed river of the supposedly damned and dead. He also appeared to be wielding a clipboard as some sort of makeshift oar while cursing quite fluently. Enough so that with a little persuasion fingers stuffed themselves into Chopper's ears.

Interesting.

The… vagrant made it to shore without too much incident.

"Nico Robin? Tonytony…" There was a pause. "Who the _fuck_ gets a name like Tonytony Chopper?"

She was privately glad the fingers were still stuffed in his ears and the little dear was giving them all very confused glances so she did the logical thing, covered his eyes and kicked the shinigami, ferryman, whatever in the crotch.

He went down. The demon woman then put a delicate hand on his throat and whispered: "Don't. Alarm. Him."

She gave him a smile.

It wasn't genuine.

He growled back at her. He was blond and short and annoyed and apparently wearing a codpiece. "Look lady-"

"Niisan! Being nice never hurt anyone."

Robin blinked. The chestpiece was… speaking. It was a boyish voice and hadn't yet deepened. She looked more closely at the armor, fascinated.

"Fine, fine, fine. When we get your body back and people are kicking you in the balls for doing your job, I'll be telling you to be nice."

"Yes, niisan."

"Alright Mr. Chopper and Mrs. Robin," the shrimp said with exaggerated care, "please sign these forms. Someone'll be around to get them processed."

Robin finally un-stuck the fingers from Chopper's ears and uncovered his eyes.

* * *

The boy in red and the talking suit of armor/boat disappeared sometime as she was mulling through the paperwork.

"They want us to fight?" Chopper squeaked as he read through his own documents. "Hades coliseum. That doesn't sound good." He sifted through the document for another moment. "But they are offering good dental."

Yes, while they were dead. And presumably not in need of dental.

Robin raised an eyebrow at him, wishing she had her reading glances. There wasn't a real need for them, but it would be nice to have something familiar while she read through contracts explaining the necessity to sell their immortal souls. She had always thought it was a little more figurative. This just sounded more like mundane slavery. She had read about gladiators, once.

"This Hades person sounds awfully confident," Chopper muttered. "Why should we even do this?"

Robin skipped to the last paragraph.

"Apparently…" she looked at it again, aghast, hopeful, wondering. "Apparently because he can bring us back to life."

* * *

Author's notes: We'll be seeing a few cameos from various places. Today we have Ed and Al from FMA. If you didn't already know. And no, I don't own em' either.


	2. Chapter 2

Disclaimer: I still claim no ownership. Oda probably still owns One Piece.

* * *

Although Nami wasn't there to help them think from the devious perspective, between the two of them Robin and Chopper had about seventy-five percent of the Strawhat crew's smarts (Nami had the other twenty-four; the rest of the men seemed to share the measly one percent) and spent the better part of a day considering the paperwork, trying to decipher the very fine print as well as the loopholes and whatever tiny bit of writing that might give them an edge.

With a lack of any real means to tell time, they might have spent weeks just reading. It certainly felt that long.

By the end of it, even Robin's head spun. Although the papers weighed no more than a thin book, it seemed to go on forever with provisions for the most unlikely scenarios, and contingencies, counter-contingencies and exigencies and hundreds, if not thousands of pages worth of footnotes and fine print.

There was also an entire section devoted to one's personal appearance and hygiene. Robin knew far more than she had ever wanted to about oiling muscles so that they glistened in unholy, ethereal light. She had the feeling they'd want her to wear very little. It seemed like that sort of place.

"_I_ should go," Robin finally said.

Chopper frowned at her.

"If there is a trick, you can rescue me. Or at least be better prepared to resist it." Robin offered. It'd be like old times. And it'd conveniently keep Chopper out of the way in case there was more to this 'Coliseum' than mere fighting.

Chopper continued to frown at her.

Robin, looked down, biting her tongue.

"We're sticking together," Chopper said, patting Robin on the shoulder. It would have been unnerving once, to see how easily she had been read, but Robin _knew_ her nakama. And they knew her. "You don't have to protect me."

_But I will_. She thought. Because he would do the same for her.

He had, come to think of it.

"Alright then," Robin said. "So shall we-"

"Sign? Yes my dearies, _do_ sign. It'll make Hades ever so ha_ppy_."

The two of them whirled around, on guard. If Robin hadn't known for a fact that octopus fishmen had six arms and two legs and not the reverse; she might have thought one such fishman – fishwoman, rather – had come ashore. She was a portly creature with mottled, purple skin on her upper body and black, nearly obsidian skin covering her tentacles and lower body. It nearly made her appear as if she were wearing a dress. The white hair made her look distinguished, somehow.

"Who are you?" Chopper asked, putting himself between Robin and the newcomer. There was a little yellow rumble ball in his hoof whose provenance Robin didn't question. She herself discretely prepared to neutralize the octopus-woman with a chokehold if it became necessary.

"My name is Ursula, dearies. I am here to grant your fondest desires."

"A bear?" Robin murmured.

"What was that?" Ursula said, looking confused. Her smiling countenance soon resumed itself. "Anyway, dearies. It sounds like you are prepared to sign." The papers started levitating from the ground, glowing bright yellow before transforming into one long scroll. A pen that appeared to be made fishbones blinked into existence. It shone like a penlight.

"All you need to do is sign the scroll."

Robin quickly scanned the… refurbished document. All the important provisions were intact. But…

"I do not think a pen was our fondest desire."

"Too true, too true, my dear." The scroll snapped shut. "You want more, I can tell. Knowledge? Perhaps that Lost Century?" She laughed at Robin's expression. "Now now dear, you have nothing I really want. The flower fruit is useful, true… But little Chopper here…"

"Not interested," Robin said, grinding her teeth.

"Sign then." The scroll unfurled. "It's your only ticket out. And your only ticket _in_."

It was all Robin could do to keep from snarling. She had met people like this before. Riddles without answers; questions with more questions. No good would come out of a continued negotiation with this one. She picked up the pen. Signed. She felt something heavy descend. A weight on her soul. Manacles appeared on her wrists and feet.

"What happened?" Chopper demanded, alarmed.

"Wouldn't _you_ want to know," Ursula said brightly. "For a little fee I could-"

"Don't, Chopper." Robin mumbled as she poked at the manacles. They stayed put.

Looking mistrustfully at Ursula, Chopper glanced at the manacles again.

"I'll throw it in for free since you're such a widdle cutie-pooh." Ursula offered magnanimously. "Robin here has signed into Hades' gladiator ring. It's an honor of sorts, you know. Most souls get to go drown in our various rivers for all of eternity. But she's still signed her soul over so-" she gestured towards the manacles, "Hades has put his mark on her. Just a little mark. Won't hamper her at all. Might even help."

"Robin?"

"They don't hurt," Robin admitted. An arm popped out of the ground. It was wearing the manacle. She did the same with her leg. Ditto. "Hmmm."

"But I-"

"Transform? Yeeees deary. Don't worry, your manacles will grow with you. Hades likes to have all his warriors in peak condition. Wouldn't really be peak if you were stuck like _that_ all the time."

"So sign, deary. Just like your friend."

Robin knew Chopper was signing more out of loyalty to her than any demand placed upon him by the strange octopus fishwoman. Mancles appeared on him and Robin felt irrationally angry. Chopper shouldn't have had to-

"Well voila!" She sent them a kiss that transformed into a business card. One for each of them. "Call me dearies if you ever need any help. Now that you're stuck like that for all eternity-"

"But he said we'd come back to life!" Chopper protested. "We read it! It was in the last paragraph. All it'd take is defeating this Ares guy-"

Ursula grinned, double chin bulging. "That, dearies, would be a wee bit troublesome. Hades is the God of Death."

Robin could feel the laugh that Ursula was trying to contain.

"But Ares, you see, is the God of War."

Then the ground beneath them opened up and they fell. She could hear Ursula waving to them even as they plummeted. They were going to quick for her to make a ladder of arms and she couldn't see where they were going-

"Buh-bye dearies, you've been _such_ a help."

* * *

Author's Notes: Will we be seeing more of Ursula? Will we ever find out what she wanted from Chopper? Who knows! For those that didn't recognize her – poor, deprived children that you are – that was Ursula from the Little Mermaid and belongs to Disney. This chapter was mostly inspired by when she took Ariel's voice. To Amethyst Turtle and Demonguard666, thanks for reviewing!


	3. Chapter 3

Disclaimer: Still not mine.

* * *

Robin had seen many things.

She'd seen the sea from above, where the air was so thin that it hurt to breathe and even her nakama's screams were being lost to the wind; she'd seen the grit-covered ground of a hidden chamber coming to meet her face in slow motion; she'd seen a dear, dying friend waiting for her in inhospitable waters after she leaped off a burning bridge; she'd seen a blue-haired cyborg look at her, amazed, as they flew; she'd…

She'd fallen through the lower rings of Hades.

Honestly? It wasn't anything special.

* * *

As they fell, Robin unfurled her wings.

In a manner of speaking.

It wasn't true flight, not exactly, but it was as close as anyone could get to it with human parts. She'd eaten the _Hana Hana No Mi_, a devil fruit that had established within her the power to grow any organ, limb or body part on any surface she could see or feel. A dozen arms sprouted from her shoulderblades, each arm branching to form another until she had achieved a near eighteen-foot wingspan.

Chopper screamed.

She flapped once, her mouth dry. She'd almost lost Chopper. Who couldn't fly. Where was he- The light from above winked once before disappearing entirely, plunging the cavern or hole into darkness. Somehow she knew they wouldn't be getting out of this via the route they had come down.

_Interesting,_ something in the dark, dank air whispered.

Robin banked hard, listening intently. She heard a faraway scream of terror and smiled thinly. Usopp, Nami, Chopper and Luffy had always enjoyed a good scare, even after they'd become targets so dangerous that the world government had practically guaranteed making whoever caught them an instant World Noble. Some things wouldn't change. A flowering of hands appeared from her backside, creating a makeshift tail.

Robin dove.

A long time ago, before the New World, before the war, before even Fishman Island, she hadn't been able to maintain flight for more than a handspan of seconds. It had merely been an inadequate novelty, good for a moment of respite from freefall. Then they had gone to the New World and it had become not merely practical but vital.

So she had learned how to fly. She had learned how to flap her arms so that they'd produce enough thrust; she had learned how to catch thermals and soar with barely any effort; how to fight in mid-air and see, even when the sun was in her eyes; she had learned how a tail-like protrusion could control direction, aid in steep verticals and sudden stops.

She had flown, half-dead, with a bleeding, dying Zoro on her back who couldn't, wouldn't stop smiling.

She could hear him, even now. '_I did it, Kuina._'

She still didn't know who Kuina was.

Chopper was still screaming when she caught him. Tears leaking out of his eyes he grabbed onto her neck, half-choking her. She could feel the little manacles, cold and pitiless. They didn't belong there. His heart beat in steady beats: he hadn't truly been scared. "Robin!" The doctor wailed. "I lost my _hat_."

Robin blinked. Felt along the top of his head. Found an antler and soft fur.

He had, in fact, lost his hat.

"We'll get it back," she told him, reassuringly. Flapping hard, she reversed their fall. All around her, she could only see darkness. She peered at what she thought was up but not even the merest speck of light shone down. She was flying blind.

"Chopper, can you-"

But before she could ask if he could see anything, something happened. It felt a bit… nostalgic. Luffy's haki. Except not. She felt her muscles freeze, her wings shudder. Careening out of control, they started falling, faster and faster and faster. She could hear Chopper's worried comments as they spiralled out of control, her 'wings' retracting automatically as she lost the ability to focus on them.

Hmmmm. Weaker than I thought-

That voice again. Robin ignored it; she had to focus on moving. First her hands- she focused on her thumbs, thought she felt something wiggle. Now her wrist- good.

"Robin? Robin? What happened?"

Faster and faster and faster- if she didn't do something soon they were going to hit the bottom and splatter. Not everyone had Luffy's rubbery constitution and imperviousness to blunt trauma. At the moment though, she was having trouble just forming coherent thought.

One step at a time. Right. She felt Chopper enter defence point, making sure to keep her on top of him, still asking her questions.

The force controlling her noticed she was moving. _I'm afraid not-_

Robin mustered her strength and released her own haki.

She felt the voice register surprise as she fought herself free from whatever had been controlling her. She took a deep, staggered breath. Tried to create wings – but no, it was too much effort too quickly. She needed to recuperate. With an violent jerk she slammed her manacles together, producing sparks. Her eyes had already gotten used to the darkness and were temporarily blinded by the glare – and then she saw a huge, vast cavern with nothing but gleaming white: and they were already near the bottom.

The two of them clenched their teeth.

The impact was terrific. Who knew how long they'd fallen. Over a four minutes? Over five? Chopper bounced like some child's ball, cracking the ground beneath and she simply fell off of him, flung away like a rag doll and feeling like she'd scraped off half the skin on her body as she was flung into a pile of debris.

She got up, bleeding from a dozen minor wounds. They didn't matter. Chopper did. She'd lost track of him. Again.

"Chopper," Robin asked, doing her level best to keep her voice steady as she swept her arms out blindly, searching for her reindeer companion, "Chopper, are you alright?"

"Robin… there's five of you…" Chopper responded, dazed from somewhere behind her. Robin angled her head back, arms sprouting for her back until she located a furry ball of surprisingly resistant fluff.

Silent sigh of relief.

"You can see, in this light?" She asked cautiously, arms disappearing as she took a few tentative steps towards him. Something brittle and dry crunched underfoot at each step. What in the world was this place made of?

"Not very well," she heard Chopper admit. Something with hooves shakily got to its feet. Whatever was beneath her feet was beneath his as well. "I'm… seeing double. I think I might have hit my head." He pawed curiously at the ground. "And there's-"

Chopper went very still.

"Robin." He whispered from the darkness, swallowing hard. "There's nothing but bones around us. Just… bones. Everywhere." His voice trailed off. He swallowed again. "Robin, I think I heard something _move._"

Robin nodded. Eyes opened all across her body, trying to catch any hint of ambient light. But if there was anything she could perceive, it was not with her eyes. She closed them. Breathed in lightly.

There was a smell… here… familiar… Robin took a deeper breath.

Death? No, something more… ancient.

There was a scent of mildew and old bones. Ages old dust and dirt. Now that she was focused on her other senses, she could feel the strands of cobweb tickling her hair.

"Mausoleum?" Robin asked, confused. Unconsciously, she wrinkled her nose.

"Robin?" Chopper asked, worried.

"I'm here." Robin said, distracted, thinking. More crunching sounds, presumably from Chopper's agitated movements.

"Robin - there's someone right _behind you._"

* * *

At first she thought, impossibly, that Brooke had died too.

Her hands skittered against the cold, dry surface of bone. It moved beneath her grasp. "_Robin,_" Chopper shouted desperately, but even without her sight Robin could hear the whistling of a swung sword and ducked appropriately. Around them, bones were rising to form animated soldiers.

Robin heard the crunching noise of bones cracking as Chopper fought to reach her.

There wasn't enough room to form wings, not with so many skeletal soldiers waving around sharp, pointy objects. Robin ducked and rolled as another sword or spear came out of nowhere. She retaliated with a punch that made a rib cage more or less explode. Flimsier than she'd expected. If she could only see she'd-

"This is like Thriller Bark all over again," Chopper groaned. More crunching noises and he added thoughtfully: "except they're really, really fragile. I wonder if Brooke would-"

_Hmmm. _

Lovely. The voice was back.

_Entertaining as this is-_

Robin was having some difficulty fighting without her sight when something grabbed her feet from below. If she were one for hysterics she might have started screaming and yelling and kicking. Since she wasn't, hadn't been since before she could remember - she had to listen to Chopper, who could easily punch out a Sea King, do it instead. Robin simply grew arms at her ankles that grabbed fingers and started breaking them.

Chopper, presumably, was kicking them into shattered fragments.

She wondered if Luffy would have just tried to give them a hand up. She stumbled towards Chopper, avoiding blows as best she could. Sometimes she wished her haki gave her the power to predict attacks. Ah well. Hers wasn't so bad either.

"Chopper," she told him, as she stumbled forwards, blade whistling where her head had previously been. She replied with a blow that shattered the arm holding the sword and heard it clang to the ground. "We have to go up. Come over here-"

_You know. No one has survived Phlegyas' Pit before on their first try. Colour me impressed. _

Chopper gave a shout and tumbled over. Robin could hear the bones skitter across him, grasping and tearing at his fur. Even before she could reach out towards him, Robin felt her limbs lock up again. With an effort, she pierced through the oppressive power. But not before more skeletal limbs had grasped hold of her. She broke them, breathing hard.

Phlegyas, Phlegyas – where had she heard that name before-

_If I had a few more eons I might let you at it, just to see how long it'd take for the two of you to be overwhelmed-_

Robin fought her way over to Chopper- feeling an unreasonable sense of dread. "Chopper- CHOPPER-"

_But Hades' getting bored._ _So we do this the hard way._

A wave of bone appeared, splitting the two of them apart before burying them in splinters.

And then everything was swallowed up by true darkness.

* * *

Author's Notes: Looking over my previous chapters I realize that this fic could _really_ use a beta. I mean Ursula was supposed to come over as creepy and self-assured and arrogant but I think I made her say deary two bajillion times. Having someone point out that sort of thing would be helpful, yeah. I'll go back at one point or another and fix it.

Thank you again to AmethystTurtle and DemonGuard666 for reviewing – you guys rock! And a thank you as well to ArashiStormGuardian and MasterCrane. :3


End file.
